title: Reference values for myocardial two-dimensional strain echocardiography in a healthy pediatric and young adult cohort.
abstract: BACKGROUND
  The accurate evaluation of intrinsic myocardial contractility in children with or without congenital heart disease (CHD) has turned out to be a challenge. Two-dimensional strain echocardiographic (2DSTE) imaging or two-dimensional speckle-tracking echocardiographic imaging appears to hold significant promise as a tool to improve the assessment of ventricular myocardial function. The aim of this study was to estimate left ventricular myocardial systolic function using 2DSTE imaging in a large cohort consisting of healthy children and young adults to establish reference strain values.
  
  
  METHODS
  Transthoracic echocardiograms were acquired in 195 healthy subjects (139 children, 56 young adults) and were retrospectively analyzed. Longitudinal, circumferential, and radial peak systolic strain values were determined by means of speckle tracking. Nonlinear regression analysis was performed to assess the effect of aging on these 2DSTE parameters.
  
  
  RESULTS
  There was a strong, statistically significant second-order polynomial relation (P < .001) between global peak systolic strain parameters and age. Global peak systolic strain values were lowest in the youngest and oldest age groups.
  
  
  CONCLUSIONS
  This is the first report to establish age-dependent reference values per cardiac segment for myocardial strain in all three directions assessed using 2DSTE imaging in a large pediatric and young adult cohort. There is a need to use age-specific reference values for the adequate interpretation of 2DSTE measurements.
authors.affiliation: Children's Heart Centre, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. k.marcus@cukz.umcn.nl
authors.forename: Karen A
authors.initials: KA
authors.lastname: Marcus
authors.forename: Annelies M C
authors.initials: AM
authors.lastname: Mavinkurve-Groothuis
authors.forename: Marlieke
authors.initials: M
authors.lastname: Barends
authors.forename: Arie
authors.initials: A
authors.lastname: van Dijk
authors.forename: Ton
authors.initials: T
authors.lastname: Feuth
authors.forename: Chris
authors.initials: C
authors.lastname: de Korte
authors.forename: Livia
authors.initials: L
authors.lastname: Kapusta
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006337:Heart Murmurs / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D012016:Reference Values; D012044:Regression Analysis; D012189:Retrospective Studies; D016277:Ventricular Function, Left / Q000502:physiology*